package model;

import com.mysql.jdbc.Connection;
import com.mysql.jdbc.PreparedStatement;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

public class BlogDao {
    //新增操作（提交博客）
    public void insert(Blog blog){
        Connection connection=null;
        PreparedStatement statement=null;
        try{
            connection=DBUtil.getConnection();
            String sql="insert into blog values(null,?,?,now(),?)";
            statement= (PreparedStatement) connection.prepareStatement(sql);
            statement.setString(1,blog.getTitle());
            statement.setString(2,blog.getContent());
            statement.setInt(3,blog.getUserId());

            statement.executeLargeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }

    //查询博客列表（博客列表页）
    public  List<Blog> getBlogs(){
        List<Blog> blogList=new ArrayList<>();
        Connection connection=null;
        PreparedStatement  statement=null;
        ResultSet resultSet=null;
        try{
            connection=DBUtil.getConnection();
            String sql="select * from blog order by postTime desc";
            statement= (PreparedStatement) connection.prepareStatement(sql);
            resultSet=statement.executeQuery();
            while(resultSet.next()){
                Blog blog=new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                String content=resultSet.getString("content");
                if(content.length()>100){
                    content=content.substring(0,100)+"....";
                }
                blog.setContent(content);
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blog.setUserId(resultSet.getInt("userId"));
                blogList.add(blog);
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection, statement, resultSet);
        }
        return blogList;
    }

    //根据博客id查询指定的博客
    public Blog getBlog(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        ResultSet resultSet = null;
        try{
            connection=DBUtil.getConnection();
            String sql="select * from blog where blogId = ?";
            statement= (PreparedStatement) connection.prepareStatement(sql);
            statement.setInt(1,blogId);
            resultSet=statement.executeQuery();
            if(resultSet.next()){
                Blog blog=new Blog();
                blog.setBlogId(resultSet.getInt("blogId"));
                blog.setTitle(resultSet.getString("title"));
                blog.setContent(resultSet.getString("content"));
                blog.setPostTime(resultSet.getTimestamp("postTime"));
                blog.setUserId(resultSet.getInt("userId"));
                return blog;
            }
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection, statement, resultSet);
        }
        return null;
    }

    //根据博客id，删除博客
    public void delete(int blogId){
        Connection connection = null;
        PreparedStatement statement = null;
        try{
            connection=DBUtil.getConnection();
            String sql="delete from blog where blogId = ?";
            statement.setInt(1,blogId);
            statement.executeUpdate();
        } catch (SQLException e) {
            throw new RuntimeException(e);
        }finally {
            DBUtil.close(connection,statement,null);
        }
    }
}
